The objectives of the Clinical Core C are: 1. To provide a central laboratory for the recruitment and characterization of normal and asthmatic subjects for the clinical components of Projects 1, 2, and 3. 2. To provide a central facility for performance and quality control of pulmonary function testing, antigen skin testing, and methacholine challenge. 3. To provide a central laboratory for collection and analysis of bronchoalveolar lavage fluid and biopsy tissue. 4. To coordinate the distribution of bronchoalveolar lavage cells and fluid, and biopsy tissue to the investigators in Projects 1, 2, and 3. 5. To coordinate the database development of all clinical and laboratory data on normal subjects and patients with asthma as well as transmittal of the data to the individual investigators. 6. To facilitate interproject communication concerning both clinical findings and technical accomplishments. In doing so, the clinical aspects of this Program Project grant will function at a high standard.